Adds hours of battery life to the expense of making your microphone input completely inaudible due to throttling if you background the tab it's running on.

On iOS you cannot even keep a web app running in the background. The second they mutlitask, even with an audio/microphone active, Apple kills it. Are they truly adding battery life or are they cheating by creating restrictions that prevent apps from working?

Being able to conduct a voice call through the browser seems like a pretty basic use case to me.